He said the impact caused the shark's body to slap against the side of his canoe, before it swam off.
He said the shark, which was about a metre long, hit his canoe really hard.
"It was a hell of a bang. He wasn't a monster, but enough to give you a fright."
Mr Kensington is out on the water most weekends. He said he might see a shark a few times a year, but this was his first up-close encounter.
"One's enough. The scary part was I had actually tipped out about five to 10 minutes beforehand."
The group was having a practice run for this weekend's Poor Knights Crossing event, which is part of the Tutukaka Coast Winter Festival.
He said he didn't realise the shark had taken a bite at first. He reached down to feel if there were any cracks, then carried on.
"It wasn't until I actually picked the canoe up out of the water that I realised it had water in it."
When he looked underneath he found the bite marks.
He didn't know what type of shark it was, but said some of the paddlers thought it might be a mako, because they tended to be more aggressive.
Saturday's outing was the new canoe's first proper run.
Mr Kensington said he was "a bit gutted" but it is easily fixable.
He plans to have it patched up and ready for the race.
